Roller plate grab



July 27, 1965 A. J. TROTTA ETAL ROLLER PLATE GRAB 3 Sheets-Sheet 1 Filed Jan. 25, 1963 Ari/bony J 770fla David A. Sudrab/h July 27, 1965 A. J. TROTTA ETAL ROLLER PLATE GRAB 3 Sheets-Sheet 2 Filed'Jan. 25, 1963 INVENTORS Ant/rany J Trofla July 27, 1965 Filed Jan. 23 1963 Fig.4

3 Sheets-Sheet 3 INVENTORS Ari/bony J 7707/0 3,197,250 Patented July 27, 1965 United States Patent (Mike 3,197,250 ROLLER PLATE GRAB Anthony J. Trotta, Pembroke, and David A. Sudrabin,

South Braintree, Mass., assignors, by 'mesne assignments, to Bethlehem Steel Corporation, a corporation of Delaware Filed Jan. 23, 1963, Ser. No. 253,438 1 Claim. (Cl. 294-102) This invention is a grab for heavy metal plates.

It is an object of the invention to provide reliable means for gripping large metal plates between smooth surfaces tightly enough to allow safe lifting and movement but without casing harmful indentations on either side surface of the plate.

Other objects, purposes and advantages of the invention will appear hereinafter in the specification and claim, and in the appended sheet of drawings.

In the drawings:

FIG. 1 is a side elevational view of the grab with the gripping rollers being shown in the down position, while a plate is being engaged;

FIG. 2 is a side elevational view of the device with the rollers, in raised position, showing two positions of the handle by which the spring pressure onthe rollers is released;

FIG. 3 is a vertical sectional view taken on the line 33 of FIG. 1; and

FIG. 4 is a horizontal section on the line 44 of FIG. 1.

Referring to the drawings, the large inverted U-shaped or horseshoe-shaped metal body 1 (which may be of one or several plates) includes an upper lug portion 2 which is suspended in conventional manner by a shackle in the hole 3. The inner surfaces of the depending leg portions 4 of the body 1 slope downwardly and inwardly toward each other and are provided with rounded triangular lower plate guides 5 and flat backing plates 6 which serve as wear plates or tracks for the two smooth surfaced rollers 7. Said rollers 7 have reduced end portions 8 which are journaled in oppositely inclined slots 9 in a pair of roller guide plates 10. Said roller guide plates 10 are substantially rectangular metal plates which are maintained with their fiat surfaces in suitable parallel relation by the interposed spacers 11. The lower edges of said guide plates 10 are preferably cut away as at 12 in order to receive plates of maximum possible width.

Mounted on each leg 4 are parallel upright guide blocks 13 between which the guide plates 10 carrying the rollers 7 are vertically slidable in proper alignment.

Even without other forces on the rollers 7, a plate 1 which is received vertically between the rollers 7 and is then lifted by this device will become wedged between the rollers 7 as they are drawn down on the sloping backing plates 6.

However, in most applications, the above-described gripping action is preferably assisted by spring pressure on the rollers 7. In the present device, the spring mechanism includes upright tension springs 14 to actuate a coactingly pivoted linkage which pushes downward the roller guide plates 10 and the rollers 7.

Said linkage is constituted by the spring extension arms 15, release lever 16, bell crank lifting arms 17 pivoting at their point of intersection on the body 1, and lifting arm extensions 18.

Each lifting arm 17 carries a'central projection 19 which when engaged by the upper end of the lever 16 will exert downward pressure on the clamping means. The upper end of the release lever 16 includes a manually operated handle 20.

In operation, my device is usually forced onto the plate 1, which is grasped between the spring-pressed rollers 7. When the grab is raised the rollers will wedge tightly against the plate, and they cannot release until the grab has been relieved of the load at the completion of the lift, regardless of the position of the spring release mechanism. When the weight of the plate is fully supported on other means, guide plates 10 will be pushed upwardly, releasing the grip of rollers 7 on the plate. Moving the handle 20 downward to the position shown in phantom in FIG. 2 removes the downward pull of springs 14 from roller guide plates 10, thereby facilitating release of plate 1 from the grip of rollers 7. Raising the handle 20 allows the springs 14 to'draw the roller downward again into plate-gripping position. It is found to be easier to grasp a very thick plate 'or slab if the springs are initially in the released position, since this will assist its entry between the rollers.

The use of confined smooth surfaces on the rollers 7 is of particular advantage in handling highly critical curved sections such as submarine hull plates, which are strictly inspected for surface defects and cannot safely be gripped between rough serrated members without risk of marring the plates or spoiling their curvature. The gripping effect is progressively cumulative and fully dependable at all times. Any indentations in the plates will be very shallow and smoothly rounded. However, protecting plates may also be placed between the rollers 7 and the section being lifted to further minimize any possible indentation of the section, if desired, and have been observed to still be held effectively even where the section was heavily lubricated.

The ends of the gripping surfaces of each of the rollers 7 may and preferably should be smoothly rounded off or radiused, as shown in the drawings, to prevent any possibility of marks due to sharp edges on the ends of the rollers being impressed on the section under extreme loads.

We claim:

A grab for gripping metal plates, comprising:

(a) an inverted U-shaped body having downwardly inwardly sloping legs,

(b) rectangular flat plate members in spaced parallel relationship on opposite sides of said body and having parallel pairs of slots inclined upwardly from said legs,

(0) a pair of smooth faced plate gripping rollers journaled in said slots,

(d) each of said plate members being cut away centrally on its lower side to admit a plate therebetween,

(e) parallel upright guide members on the legs between which the plate members slide vertically outside the legs,

(f) an upright tension spring having its lower end pivotally connected to one leg of thebody,

(g) a link connected to the upper end of said spring,

(h) a release lever having its intermediate portion pivoted to said link,

(i) a bell crank member having depending and lateral arms at right angles to each other,

(1') said bell crank being pivotally mounted on the grab body at the point of intersection of said arms,

(k) the lower end of the release lever being pivotally connected to the lower end of the depending arm,

(I) the intermediate portion of the lateral arm bearing an external projection,

(m) the far end of said lateral arm having a downward link pivotally connected to a plate member, (11) the lateral arm being urged downwardly by the action of the tension spring and release lever exerting pressure on said projection, and

w (o) the downward pressure on said lateral arm being released when said release lever is rotated about its pivot point.

References Cited by the Examiner UNITED STATES PATENTS 901,925 10/08 Thompson 294-86 1,221,400 4/17 Wilhelm 294-102 XR 2,559,223 7/51 Murray 94102 3,008,749 11/61 Gowan" 294-116 XR SAMUEL F. COLEMAN, Primary Examiner.

ERNEST A. FALLER, Examiner. 

